Disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate

Endpoint summary

Description of key information

Appearance / physical state / colour:
On basis of standard methods of analysis, Disodium 4,4’-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bis-azo)di-(naphthalene-1-sulfonate) was found to be in the form of dark brown powder.

Melting point:
The decomposition temperature of Disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) is determined to be 330°C at 976.4hPa.

Boiling point:

The study does not need to be conducted because the substance is a solid which decomposes before boiling

Density:
The pour density and tapped density of disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) were determined to be 0.6318 gm/cm3 and 0.8163 gm/cm3 at 29.9 °C and 975.2 hPa, respectively.

Particle size distribution (Granulometry):
The particle size distribution of test substance Disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was found to be in the range of 150 micron to 10 micron.

Vapour pressure:
The vapour pressure of the substance Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is determined to be 1.48E-33 mm Hg at 25°C which is < 0.0000000000001 mm Hg. This value is equivalent to 1.97E-31 Pascal at 25°C.

Partition coefficient:
The partition coefficient of test substance disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate(CAS No.4553-89-3)was determined as per the HPLC method (OECD Guideline-117). The Log Pow value was determined to be 4.496± 0.011 at 25°C.

Water solubility:
The water solubility determination of test item Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) CAS No.4553-89-3 was done by HPLC. The mean water solubility was determined to be 99418 mg/l (99.418 g/L) at 25°C. Thus the chemical is considered to be very soluble.

Solubility in organic solvents/ fat solubility:
The solubility range of the test item Disodium -4,4’-[2,4-dihydrox-5-(hydoxymehyl)-1,3-phenylene]bis(azo)bisnapthalene-1-sulphonate in acetone was determined to be greater than 1000-200 g/l and 100-50 g/l in case of ethanol and methanol whereas the solubility value in acetonitrile, toluene and DMF was determined to be greater than 1g/l respectively at 28 °C.

Surface tension:
In accordance with column 2 of Annex VII of the REACH regulation, this end point was considered for waiver since surface activity is not a desired property of the material considering its use as a food colour.

Flash point:
The mean flash point of disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) is determined to be 182°C at 975 hPa.

Auto-flammability:
Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) did not catch fire on being exposed to air at room temperature of 27°C pressure of 966 hPa. This indicates that Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is not auto-flammable.

Flammability:
The chemical disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (Synonym: C.I. Food Brown 3) is a food color and is not likely to be flammable. Therefore testing for this end point was considered to be scientifically unjustified.

Explosiveness:

Based on the experiment conducted,the chemical  Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) was observed to be non-explosive under the test condition.

Oxidising properties:
This end point was considered for waiver since in accordance with column 2 of Annex VII, this study does not need to be conducted as the substance is incapable of reacting exothermically with combustible materials, on the basis of the chemical structure. The chemical contains oxygen (no halogen) but oxygen is not chemically bonded to nitrogen or oxygen. Thus, the chemical is not likely to exhibit oxidising properties.

pH:
pH of 1% w/v aqueous solution of the test item disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) is determined to be 4.5 at 24.9°C.

Additional information

Appearance / physical state / colour:
On basis of standard methods of analysis, Disodium 4,4’-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bis-azo)di-(naphthalene-1-sulfonate) was found to be in the form of dark brown powder.

Supporting data from handbook and secondary source also indicates the substance Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) to be reddish-brown powder or granules.

Melting point:
The melting point determination of test item Disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was done as per the test guideline OECD 102. The method followed was according to Capillary/metal block. The decomposition temperature of Disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) is determined to be 330°C at 976.4hPa.

Although the supporting predicted data from EPI suite suggests that the substance gets melted at 349.84°C rather than getting decomposed, but considering the experimental data as key study it can be concluded that the test substance gets degraded before melting.

Boiling point:

The study does not need to be conducted because the substance is a solid which decomposes before boiling.

Density:
The density of test item disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was determined following OECD guideline OECD 109 according to pour and tap density method. The pour density and tapped density of the test item were determined to be 0.6318 gm/cm3 and 0.8163 gm/cm3 at 29.9 °C and 975.2 hPa, respectively.

Particle size distribution (Granulometry):
The particle size distribution of test substance Disodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was found to be in the range of 150 micron to 10 micron.

Vapour pressure:
The vapour pressure of the substance Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is found to be 1.48E-33 mm Hg at 25°C which is < 0.0000000000001 mm Hg. This value is equivalent to 1.97E-31 Pascal at 25°C.

However due to restriction in above key value field, the value considered for CSR is 0.000000001 Pa. This value indicates that the chemical has extremely low vapour pressure.

Partition coefficient:
The partition Coefficient n-octanol/water ofdisodium 4,4’-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate(CAS No. 4553-89-3) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 117 for Testing of Chemicals. The reference substances were chosen according to structural similarity with the test substance. The reference substances were4 Acetyl pyridine, phenol, benzene, Toluene, Naphthalene, Biphenyl, N butyl benzene having Pow value ranging from 0.5 to 4.6. The Log Pow value was determined to be 4.496± 0.011at 25°C.

Other supporting data also indicates the Log Pow value for the test substance Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) as 4.18 which is close to selected key value.

Water solubility:
The water solubility determination of test item Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) CAS No.4553-89-3 was done by HPLC. The mean water solubility was determined to be 99418 mg/l (99.418 g/L) at 25°C. Thus the chemical is considered to be very soluble.

Other supporting data also indicates the test substance Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) to be soluble in water.

Solubility in organic solvents/ fat solubility:
The solubility range of the test item Disodium -4,4’-[2,4-dihydrox-5-(hydoxymehyl)-1,3-phenylene]bis(azo)bisnapthalene-1-sulphonate in acetone was determined to be greater than 1000-200 g/l and 100-50 g/l in case of ethanol and methanol whereas the solubility value in acetonitrile, toluene and DMF was determined to be greater than 1g/l respectively at 28 °C.

Surface tension:
In accordance with column 2 of Annex VII of the REACH regulation, this end point was considered for waiver since surface activity is not a desired property of the material considering its use as a food colour.

Flash point:
The flash point determination of Test item disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was done. The method is closed cup method using Pensky-Martens Flash Point Apparatus. The flashpoint of the test item was determined to be 182°C at 975 hPa.

Auto-flammability:

Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) did not catch fire on being exposed to air at room temperature of 27°C pressure of 966 hPa. This indicates that Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is not auto-flammable.

Flammability:
The chemical disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (Synonym: C.I. Food Brown 3) is a food color and is not likely to be flammable. Therefore testing for this end point was considered to be scientifically unjustified.

Explosiveness:

Based on the experiment conducted,the chemical  Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) was observed to be non-explosive under the test condition.

Oxidising properties:
This end point was considered for waiver since in accordance with column 2 of Annex VII, this study does not need to be conducted as the substance is incapable of reacting exothermically with combustible materials, on the basis of the chemical structure. The chemical contains oxygen (no halogen) but oxygen is not chemically bonded to nitrogen or oxygen. Thus, the chemical is not likely to exhibit oxidising properties.

pH:
pH of 1% w/v aqueous solution of the test item disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) is determined to be 4.5 at 24.9°C. Thus, 1% solution can be considered to be slightly acidic in nature.